1. Introduction 2. FRP for Structural Strengthening. 3. Beam, Slab and Column Strengthening

Transcription

1 Structural using Advanced FRP Technology Contents 1. Introduction 2. FRP for Structural 3. Beam, Slab and Column FYFE (Hong Kong) Limited Unit 7, 20/F., Block B, New Trade Plaza 6 On Ping Street, Shatin, Hong Kong Tel: ; Fax: Fibrwrap 1. Introduction FRP - Fibre Reinforced Polymer A matrix of polymeric material reinforced by natural or synthetic fibres FRP Applications in Aeronautical and Automotive Industries + = Advantageous Characteristics High strength 2~10 times higher than steel Low weight Weight only 20% Durability FRP in Structural - High strength less materials required - Low weight easy handling, safety & speed - Durability no corrosion - Formability can adapt to any structural shape Stealth and Formability 1

2 Fyfe (Hong Kong) Limited a subsidiary of Aegion Corporation Energy & Mining Water & Wastewater Commercial & Structural H.Q.in USA with branches world-wide Regional H.Q. Fyfe (Asia) Pte Ltd (Singapore) Fyfe (Hong Kong) Limited Scope of services:- Structural strengthening Cathodic protection Concrete repairs Other specialized works Classification Methods i) Fibre types: Glass fibres, Carbon fibres, or ii) Aramid (Kevlar ) fibres Method of forming: Wet-lay Prefabricated plates Wet-lay FRP system Definition: dry fibre sheets or fabrics impregnated with epoxy resin on site Pre-fabricated FRP system Product Range Definition: Pre-cured composites fabricated offsite Different application requires different system System characteristics include:- Strength Stiffness Elongation Impact resistance 2

3 TYFO Wet-lay Products SEH Glass Wet-Lay SCH Carbon SAH Aramid Mechanical Properties BC WEB SEH-51 SCH-41 (carbon) Ultimate tensile strengthe (MPa) SEH25 SEH51 SEH55 WEB BC240 SCH41 SCH41S SCH35 SCH11UP SAH25 SAH51 WAB Modulus of elasticity (GPa) Max. elongation (%) Laminate thickness (mm) TYFO Pre-fabricated Product Range Mechanical Properties Pre-cured Laminates UG Glass UC Carbon SEH-51 SCH-41 (carbon) Ultimate tensile strengthe (MPa) Modulus of elasticity (GPa) UG UC-M Strips (carbon) UG55 UG75 UC55 UC75 Max. elongation (%) Laminate thickness (mm) varies varies 2. FRP for Structural i) Material degradation Why strengthening Traditional methods FRP Solution Rebar corrosion and concrete spalling Alkali-silica reaction 3

4 ii) Design errors iii) Construction Oversight Insufficient rebar Under provision of reinforcement Wrong concrete grade specified Poor concrete quality iv) Accidental Damages v) Over-loading Earthquake damages / terrorist attack Fire damage Additional floor added without strengthening vi) Change of use Traditional Methods Concrete Jacketing Advantages Established method Simple design approach Economical Hotel Rendezvous Singapore Nanjing Central Bus Station Disadvantages Bulky formwork Time consuming Disruptive Additional dead weight. Significant dimensional increase 4

5 Traditional Methods - Steel Plate Bonding Advantages Established method Economical Disadvantages Bulky set-up. Labour intensive Drilling & bolting damage structures Change aesthetics Corrosion problem Traditional Methods - Sprayed Concrete Advantages Established method Simple design approach Economical Disadvantages Specialist equipment required Messy Uneven surface finish. Additional weight and dimensions Fibrwrap - the solution! Fibrwrap strengthening to:- 1 Main Advantages:- Non-disruptive & Fast Durable Economical Aesthetically appealing 3. Beam, Slab and Column Flexural Shear Columns Axial Load strengthening Design approaches Installations Fibrwrap 5

6 Flexural : FRP bonded to beam surfaces as additional tension or compression reinforcement. System Testing with Fibrwrap Beam FlexuraI tests IIT Chennai- India Negative Moment Reinforcement Control 62% increase in the flexure capacity with 2-layers Fibrwrap Strengthened Positive Moment Reinforcement System Testing with Fibrwrap Flexure Tests on Slabs at NUS, Singapore 25% increase in the flexural capacity in the slab specimen strengthened with a single strip of Fibrwrap Shear Enhancement FRP applied to side surfaces as if stirrup reinforcement Fibre Anchor Control Strengthened Column Shear Beam Shear Shear Enhancement FRP applied to side surfaces as if stirrup reinforcement System Testing with Fibrwrap B.C. Canada 6

7 Column Axial Load : FRP applied to column external surface and act as confinement. Compressive Strength, MPa Concrete Grade, MPa Effect of Confinement (from Properties of Concrete by Adam Neville) Circular Column + = Confinement by links Confinement by TYFO Total stress effect INCREASE IN AXIAL LOAD CAPACITY UP TO 100% DUE TO CONFINEMENT System Testing with Fibrwrap Column Axial Load Tests at NUS, Singapore STRENGTHENED SPECIMEN: 2-layers C-shaped wrap 2-layers confining wrap Increase in Axial Capacity = 49% Available Design Guidelines Code/ Report Issued by Date AC125 ICBO (International Conference of Building Officials- California USA) April 1997 ACI 440 ACI (American Concrete Institute) July 2000 CONRTOL TR 55 TR 57 Technical Reports The Concrete Society, UK STRENGTHENED fib TR9.1 Bulletin 14 CAN/CSA S fib (Federation International du Beton, EU) July 2001 National Standard of Canada May 2004 Installations (1) Installations (2) Surface preparation Priming Fibrwrapping Curing Finishes 7